<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Vue 测试实例</title>
  <script src="https://unpkg.com/vue@next"></script>
</head>
<body>
<div id="conditional-rendering">
<span v-if="seen">现在你看到我了</span>
</div>

<script>
  const ConditionalRendering = {
    data() {
      return {
        seen: true
      }
    }
  }

  Vue.createApp(ConditionalRendering).mount('#conditional-rendering')
</script>
</body>
</html>